Rates of inappropriate laboratory testing, 1997-2012.

Subgroup Summary Statistics.
aP for stratum differences is meaningful only when there is a natural ordering for categories. P for difference of means: chemistry vs. hematology, P = 0.05; chemistry vs. microbiology, P = 0.65; chemistry vs. molecular, P = 0.17; hematology vs. microbiology, P = 0.43; hematology vs. molecular, P = 0.07; microbiology vs. molecular, P = 0.19.

亚组汇总统计。
分层差异的aP仅当分类存在自然排序时具有统计学意义。均值差异的P值：临床化学检验与血液学检验，P=0.05；临床化学检验与微生物学检验，P=0.65；临床化学检验与分子检验，P=0.17；血液学检验与微生物学检验，P=0.43；血液学检验与分子检验，P=0.07；微生物学检验与分子检验，P=0.19。